In recent years, there have been serious demands for silver halide photographic light-sensitive material (hereinafter sometimes referred simply to as a light-sensitive material) higher in sensitivity and image-quality higher and more stabilized in photographically aging characteristics, and various improvements of the techniques mainly of silver halide emulsions have been studied.
On the other hand, in the steps for developing a silver halide photographic light-sensitive material, a high-temperature and high-speed process has been rapidly popularized. Also when processing various kinds of silver halide photographic light-sensitive materials by making use of an automatic processor, the processing time has been shortened. For achieving a rapid processing, it has been demanded to obtain a satisfactory sensitivity and contrast gradation within a short time.
About the improvements in the color reproducibility of a silver halide color photographic light-sensitive material, Japanese Patent Publication Open to Public Inspection (hereinafter referred to as JP OPI Publication) No. 3-168734/1991 describes a monodisperse type silver halide twinned crystal emulsion having a ratio of a grain-size/a grain-thickness of less than 5, wherein, however, any roundish grain configuration after the grain is grown up is not described at all.
JP Examined Publication No. 4-33019/1992 describes a normal crystal emulsion in which silver iodide is localized inside thereof and the grains thereof are made roundish in configuration, wherein, however, a pressure-resistance improvement is mainly described, but any aging preservability (including, for example, any preservability under the conditions of a high humidity) is not described at all. Therefore, any more excellent technique has been demanded to be developed, because the above-mentioned conventional techniques have had a limit to make both aging preservability and development progress compatible, and have not been satisfactory to obtain the stability and rapid processability of the photographic characteristics which have been demanded to the recent light-sensitive materials.